WO2020133243A1 - Power supply circuit - Google Patents

Power supply circuit Download PDF

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Publication number
WO2020133243A1
WO2020133243A1 PCT/CN2018/124966 CN2018124966W WO2020133243A1 WO 2020133243 A1 WO2020133243 A1 WO 2020133243A1 CN 2018124966 W CN2018124966 W CN 2018124966W WO 2020133243 A1 WO2020133243 A1 WO 2020133243A1
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WO
WIPO (PCT)
Prior art keywords
power supply
supply circuit
switch
additional capacitor
circuit according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CN2018/124966
Other languages
French (fr)
Inventor
Qiuxiang MAO
Zhiwen Chen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tridonic GmbH and Co KG
Original Assignee
Tridonic GmbH and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tridonic GmbH and Co KG filed Critical Tridonic GmbH and Co KG
Priority to GB2110719.8A priority Critical patent/GB2594659B/en
Priority to PCT/CN2018/124966 priority patent/WO2020133243A1/en
Publication of WO2020133243A1 publication Critical patent/WO2020133243A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/42—Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
    • H02M1/4208—Arrangements for improving power factor of AC input
    • H02M1/4266—Arrangements for improving power factor of AC input using passive elements
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of DC power input into DC power output
    • H02M3/01—Resonant DC/DC converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of DC power input into DC power output
    • H02M3/02—Conversion of DC power input into DC power output without intermediate conversion into AC
    • H02M3/04—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters
    • H02M3/06—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using resistors or capacitors, e.g. potential divider
    • H02M3/07—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using resistors or capacitors, e.g. potential divider using capacitors charged and discharged alternately by semiconductor devices with control electrode, e.g. charge pumps
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of DC power input into DC power output
    • H02M3/22—Conversion of DC power input into DC power output with intermediate conversion into AC
    • H02M3/24—Conversion of DC power input into DC power output with intermediate conversion into AC by static converters
    • H02M3/28—Conversion of DC power input into DC power output with intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate AC
    • H02M3/325—Conversion of DC power input into DC power output with intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate AC using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of DC power input into DC power output with intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate AC using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33569—Conversion of DC power input into DC power output with intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate AC using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
    • H02M3/33571—Half-bridge at primary side of an isolation transformer
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0048—Circuits or arrangements for reducing losses
    • H02M1/0054—Transistor switching losses
    • H02M1/0058—Transistor switching losses by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0067—Converter structures employing plural converter units, other than for parallel operation of the units on a single load
    • H02M1/007—Plural converter units in cascade
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P80/00—Climate change mitigation technologies for sector-wide applications
    • Y02P80/10—Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier

Definitions

  • Embodiments of the present disclosure generally relate to the field of electrical apparatus, and more particularly to a power supply circuit.
  • the input voltage may be AC (Alternative Current) voltage
  • the output voltage may be DC voltage, which can be applied to a lighting device, such as LED (Light Emission Diode) etc.
  • the power supplier may form a driver for a light source as a lighting device, such as a LED.
  • Power factor is used to evaluate a utilization degree of power.
  • a passive power factor correction (PPFC) circuit is used to improve the power factor of the power supply.
  • a LLC converter is also used to provide constant current for a lamp.
  • an output voltage range and an output current range for diming application are limited because a pump current of the PPFC circuit is from an output stage of a LLC converter, which is relative low.
  • a pump current of the PPFC circuit is from an output stage of a LLC converter, which is relative low.
  • Vbus ECAP voltage, LLC transistor and resonant inductor to handle thermal problem and meet harmonic requirement is necessary.
  • harmonic in the light source may not be met the requirement in some points of a voltage and current of a primary transformer of the LLC converter.
  • embodiments of the present disclosure provide a power supply circuit.
  • an additional capacitor is used to change capacitance of the LLC converter or the charge pump circuit.
  • the pump charge boosting of the PPFC circuit is increased, and the ranges of output voltage and output current are wider.
  • the dimming application is possible.
  • harmonic requirement is easily met with low cost.
  • a power supply circuit including: a passive power factor correction (PPFC) circuit, including a charge pump circuit; a LLC converter; and an additional capacitor used to change capacitance of the LLC converter or the charge pump circuit.
  • PPFC passive power factor correction
  • the additional capacitor is inserted in parallel with a capacitor of the LLC converter.
  • the power supply circuit further includes: a first switch used to turn on the additional capacitor when a predetermined condition is satisfied.
  • the first switch includes two field effect transistors (FETs) .
  • the additional capacitor is inserted in parallel with a capacitor of the charge pump circuit.
  • the power supply circuit further includes: a second switch used to turn on the additional capacitor when the predetermined condition is satisfied.
  • the second switch includes one field effect transistor (FET) .
  • FET field effect transistor
  • the power supply circuit further includes: a driver used to drive the first switch or the second switch to turn on the additional capacitor when the predetermined condition is satisfied.
  • the driver includes an isolator and a controller.
  • the controller is used to control the isolator to drive the first switch or the second switch according to a harmonic requirement.
  • the controller is used to control the isolator to drive the first switch or the second switch according to detecting results of voltages and current of a primary transformer of the LLC converter.
  • the isolator is an optocoupler.
  • the controller is a microcontroller unit (MCU) .
  • MCU microcontroller unit
  • the power supply circuit is a LED power supply circuit.
  • an additional capacitor is used to change capacitance of the LLC converter or the charge pump circuit.
  • the pump charge boosting of the PPFC circuit is increased, and the ranges of output voltage and output current are wider.
  • the dimming application is possible.
  • harmonic requirement is easily met with low cost.
  • Fig. 1 is a diagram of a power supply circuit with an embodiment of the present disclosure
  • Fig. 2 is a diagram of detecting results of the voltages and current of the primary transformer of the LLC converter with an embodiment of the present disclosure
  • Fig. 3 is another diagram of a power supply circuit with an embodiment of the present disclosure.
  • the terms “first” and “second” refer to different elements.
  • the singular forms “a” and “an” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
  • the term “based on” is to be read as “based at least in part on. ”
  • the term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ”
  • the term “another embodiment” is to be read as “at least one other embodiment. ”
  • Other definitions, explicit and implicit, may be included below.
  • a power supply circuit is provided in a first embodiment.
  • Fig. 1 is a diagram of a power supply circuit with an embodiment of the present disclosure. As shown in Fig. 1, the power supply circuit includes:
  • a passive power factor correction (PPFC) circuit including a charge pump circuit
  • the power supply circuit may be provided for a lamp.
  • the power supply circuit is a LED power supply circuit.
  • the power supply circuit may be any type of power supply circuit.
  • the power supply is dimmable with PWM (Pulse Width Modulation) , or amplitude modulation or a combination of PWM and amplitude modulation.
  • PWM Pulse Width Modulation
  • amplitude modulation or a combination of PWM and amplitude modulation.
  • the additional capacitor may be inserted in parallel with a capacitor of the LLC converter.
  • the capacitance of the additional capacitor may be determined according to actual requirements.
  • the additional capacitor is a capacitor C9.
  • the LLC converter includes an inductor L1, diodes D1, D2, D3, D4, D10, field effect transistors Q1, Q2, resistances R1, R2, transformer TX1, and capacitors C2, C3, C5, C8, C10. Functions of these parts may be similar to those in the related art, and more details shall not be described herein any further.
  • the additional capacitor C9 is inserted in parallel with the capacitor C5 of the LLC converter.
  • the passive power factor correction (PPFC) circuit includes diodes D5, D6, D7, D8, D9, capacitors C1 and C4.
  • the charge pump circuit may include the capacitor C1 and the diode D9, which provide charge pump boosting for the capacitor C4. Functions of these parts may be similar to those in the related art, and more details shall not be described herein any further.
  • the power supply circuit may further include a filter circuit.
  • the filter circuit includes inductor L2 and capacitors C6, C7.
  • the power supply circuit may further include a first switch used to turn on the additional capacitor when a predetermined condition is satisfied.
  • the predetermined condition may be a harmonic requirement being not met.
  • the first switch includes two field effect transistors (FETs) .
  • the first switch includes FETs Q3 and Q4, which control bilateral directions of current flowing through the additional capacitor C9, so as to switch the additional capacitor C9.
  • the FETs Q3 and Q4 are connected to the capacitor C10 of the LLC converter, so as to be able to provide power for the additional capacitor C9 when the additional capacitor C9 is turned on by the FETs Q3 and Q4.
  • a resistance R3 may be included in the first switch.
  • the power supply circuit may further include a driver used to drive the first switch to turn on the additional capacitor when the predetermined condition is satisfied.
  • the driver may include an isolator and a controller.
  • the isolator may be any type of isolator.
  • the isolator is an optocoupler.
  • the controller may be any type of controller.
  • the controller is a microcontroller unit (MCU) .
  • MCU microcontroller unit
  • the driver includes an optocoupler U1 and a MCU.
  • the optocoupler U1 is also connected to the capacitor C10 of the LLC converter, so as to be able to provide auxiliary power for the additional capacitor C9 when the additional capacitor C9 is turned on by the FETs Q3 and Q4.
  • the MCU is used to control the optocoupler U1 to drive the FETs Q3 and Q4 according to a harmonic requirement.
  • the MCU controls the optocoupler U1 to drive the FETs Q3 and Q4 to turn on the additional capacitor C9. Then more power may be provided for the charge pump circuit, thus the pump charge boosting of the PPFC circuit is increased.
  • the harmonic may not be detected directly. Voltages and current of a primary transformer of the LLC converter may be detected to estimate a status of the harmonic.
  • the voltages and current of the primary transformer of the LLC converter may be detected by using existing methods.
  • Fig. 2 is a diagram of detecting results of the voltages and current of the primary transformer of the LLC converter with an embodiment of the present disclosure.
  • the upper curve represents the maximum voltages of the primary transformer of the LLC converter
  • the curve below represents the minimum voltages of the primary transformer of the LLC converter.
  • detecting results of the voltages and current of the primary transformer of the LLC converter may be acquired by the MCU. Then the MCU controls the optocoupler U1 to drive the FETs Q3 and Q4 to turn on the additional capacitor C9 when the two curves of the voltages and current of the primary transformer of the LLC converter are overlapping to each other.
  • an additional capacitor is used to change capacitance of the LLC converter.
  • the pump charge boosting of the PPFC circuit is increased, and the ranges of output voltage and output current are wider.
  • the dimming application is possible.
  • harmonic requirement is easily met with low cost.
  • a power supply circuit is provided in a second embodiment.
  • Fig. 3 is another diagram of a power supply circuit with an embodiment of the present disclosure.
  • the power supply circuit includes:
  • a passive power factor correction (PPFC) circuit including a charge pump circuit
  • the power supply circuit may be provided for a lamp.
  • the power supply circuit is a LED power supply circuit.
  • the power supply circuit may be any type of power supply circuit.
  • the power supply is dimmable with PWM (Pulse Width Modulation) , or amplitude modulation or a combination of PWM and amplitude modulation.
  • PWM Pulse Width Modulation
  • amplitude modulation or a combination of PWM and amplitude modulation.
  • the additional capacitor may be inserted in parallel with a capacitor of the charge pump circuit.
  • the capacitance of the additional capacitor may be determined according to actual requirements.
  • the additional capacitor is the capacitor C9.
  • the passive power factor correction (PPFC) circuit includes diodes D5, D6, D7, D8, D9, capacitors C1 and C4.
  • the charge pump circuit may include the capacitor C1 and the diode D9, which provide charge pump boosting for the capacitor C4. Functions of these parts may be similar to those in the related art, and more details shall not be described herein any further.
  • the additional capacitor C9 is inserted in parallel with the capacitor C1 of the charge pump circuit.
  • the LLC converter includes an inductor L1, diodes D1, D2, D3, D4, D10, field effect transistors Q1, Q2, resistances R1, R2, transformer TX1, and capacitors C2, C3, C5, C8, C10. Functions of these parts may be similar to those in the related art, and more details shall not be described herein any further.
  • the power supply circuit may further include a filter circuit.
  • the filter circuit includes inductor L2 and capacitors C6, C7.
  • the power supply circuit may further include a second switch used to turn on the additional capacitor when a predetermined condition is satisfied.
  • the predetermined condition may be a harmonic requirement being not met.
  • the second switch includes one field effect transistors (FETs) .
  • FETs field effect transistors
  • the second switch includes the FET Q3, which control one direction of current flowing through the additional capacitor C9, so as to switch the additional capacitor C9.
  • the FET Q3 is connected to the capacitor C10 of the LLC converter, so as to be able to provide power for the additional capacitor C9 when the additional capacitor C9 is turned on by the FET Q3.
  • the charge pump circuit includes the diode D9, which control the other direction of current flowing through the additional capacitor C9.
  • the diode D9 which control the other direction of current flowing through the additional capacitor C9.
  • the power supply circuit may further include a driver used to drive the second switch to turn on the additional capacitor when the predetermined condition is satisfied.
  • the driver may include an isolator and a controller.
  • the isolator may be any type of isolator.
  • the isolator is an optocoupler.
  • the controller may be any type of controller.
  • the controller is a microcontroller unit (MCU) .
  • MCU microcontroller unit
  • the driver includes the optocoupler U1 and the MCU.
  • the optocoupler U1 is also connected to the capacitor C10 of the LLC converter, so as to be able to provide auxiliary power for the additional capacitor C9 when the additional capacitor C9 is turned on by the FET Q3.
  • the MCU is used to control the optocoupler U1 to drive the FET Q3 according to a harmonic requirement.
  • the MCU controls the optocoupler U1 to drive the FET Q3 to turn on the additional capacitor C9. Then more power may be provided for the charge pump circuit, thus the pump charge boosting of the PPFC circuit is increased.
  • the harmonic may not be detected directly. Voltages and current of a primary transformer of the LLC converter may be detected to estimate a status of the harmonic.
  • the FET Q3 shall be driven to turn on the additional capacitor C9 by the optocoupler U1 and the MCU.
  • detecting results of the voltages and current of the primary transformer of the LLC converter may be acquired by the MCU. Then the MCU controls the optocoupler U1 to drive the FET Q3 to turn on the additional capacitor C9 when the two curves of the voltages and current of the primary transformer of the LLC converter are overlapping to each other.
  • an additional capacitor is used to change capacitance of the charge pump circuit.
  • the pump charge boosting of the PPFC circuit is increased, and the ranges of output voltage and output current are wider.
  • the dimming application is possible.
  • harmonic requirement is easily met with low cost.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)

Abstract

A power supply circuit. An additional capacitor is used to change capacitance of the LLC converter or the charge pump circuit. Thus, the pump charge boosting of the PPFC circuit is increased, and the ranges of output voltage and output current are wider. The dimming application is possible. Furthermore, harmonic requirement is easily met with low cost.

Description

POWER SUPPLY CIRCUIT TECHNICAL FIELD
Embodiments of the present disclosure generally relate to the field of electrical apparatus, and more particularly to a power supply circuit.
BACKGROUND
This section introduces aspects that may facilitate better understanding of the present disclosure. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art.
In the field of lighting technology, a power supplier is needed to convert input voltage to output voltage. The input voltage may be AC (Alternative Current) voltage, and the output voltage may be DC voltage, which can be applied to a lighting device, such as LED (Light Emission Diode) etc. The power supplier may form a driver for a light source as a lighting device, such as a LED.
Power factor is used to evaluate a utilization degree of power. In some cases, a passive power factor correction (PPFC) circuit is used to improve the power factor of the power supply. And a LLC converter is also used to provide constant current for a lamp.
SUMMARY
Inventors of this disclosure found that in the above existing light source, an output voltage range and an output current range for diming application are limited because a pump current of the PPFC circuit is from an output stage of a LLC converter, which is relative low. For a fixed output application, keeping increasing key bulk components, Vbus ECAP voltage, LLC transistor and resonant inductor to handle thermal problem and meet harmonic requirement is necessary. Furthermore, for dimming application, harmonic in the light source may not be met the requirement in some points of a voltage and current of a primary transformer of the LLC converter.
In general, embodiments of the present disclosure provide a power supply circuit. In the embodiments, an additional capacitor is used to change capacitance of the LLC converter or the charge pump circuit. Thus, the pump charge boosting of the PPFC circuit is increased, and the ranges of output voltage and output current are wider. The dimming application is possible. Furthermore, harmonic requirement is easily met with low cost.
In a first aspect, there is provided a power supply circuit, including: a passive power factor correction (PPFC) circuit, including a charge pump circuit; a LLC converter; and an additional capacitor used to change capacitance of the LLC converter or the charge pump circuit.
In an embodiment, the additional capacitor is inserted in parallel with a capacitor of the LLC converter.
In an embodiment, the power supply circuit further includes: a first switch used to turn on the additional capacitor when a predetermined condition is satisfied.
In an embodiment, the first switch includes two field effect transistors (FETs) .
In an embodiment, the additional capacitor is inserted in parallel with a capacitor of the charge pump circuit.
In an embodiment, the power supply circuit further includes: a second switch used to turn on the additional capacitor when the predetermined condition is satisfied.
In an embodiment, the second switch includes one field effect transistor (FET) .
In an embodiment, the power supply circuit further includes: a driver used to drive the first switch or the second switch to turn on the additional capacitor when the predetermined condition is satisfied.
In an embodiment, the driver includes an isolator and a controller.
In an embodiment, the controller is used to control the isolator to drive the first switch or the second switch according to a harmonic requirement.
In an embodiment, the controller is used to control the isolator to drive the first  switch or the second switch according to detecting results of voltages and current of a primary transformer of the LLC converter.
In an embodiment, the isolator is an optocoupler.
In an embodiment, the controller is a microcontroller unit (MCU) .
In an embodiment, the power supply circuit is a LED power supply circuit.
According to various embodiments of the present disclosure, an additional capacitor is used to change capacitance of the LLC converter or the charge pump circuit. Thus, the pump charge boosting of the PPFC circuit is increased, and the ranges of output voltage and output current are wider. The dimming application is possible. Furthermore, harmonic requirement is easily met with low cost.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other aspects, features, and benefits of various embodiments of the disclosure will become more fully apparent, by way of example, from the following detailed description with reference to the accompanying drawings, in which like reference numerals or letters are used to designate like or equivalent elements. The drawings are illustrated for facilitating better understanding of the embodiments of the disclosure and not necessarily drawn to scale, in which:
Fig. 1 is a diagram of a power supply circuit with an embodiment of the present disclosure;
Fig. 2 is a diagram of detecting results of the voltages and current of the primary transformer of the LLC converter with an embodiment of the present disclosure;
Fig. 3 is another diagram of a power supply circuit with an embodiment of the present disclosure.
DETAILED DESCRIPTION
The present disclosure will now be discussed with reference to several example embodiments. It should be understood that these embodiments are discussed only for the purpose of enabling those skilled persons in the art to better understand and thus implement the present disclosure, rather than suggesting any limitations on the scope of the present disclosure.
As used herein, the terms “first” and “second” refer to different elements. The singular forms “a” and “an” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises, ” “comprising, ” “has, ” “having, ” “includes” and/or “including” as used herein, specify the presence of stated features, elements, and/or components and the like, but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof. The term “based on” is to be read as “based at least in part on. ” The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ” The term “another embodiment” is to be read as “at least one other embodiment. ” Other definitions, explicit and implicit, may be included below.
First embodiment
A power supply circuit is provided in a first embodiment.
Fig. 1 is a diagram of a power supply circuit with an embodiment of the present disclosure. As shown in Fig. 1, the power supply circuit includes:
a passive power factor correction (PPFC) circuit, including a charge pump circuit;
a LLC converter; and
an additional capacitor used to change capacitance of the LLC converter.
In an embodiment, the power supply circuit may be provided for a lamp. For example, the power supply circuit is a LED power supply circuit.
In an embodiment, the power supply circuit may be any type of power supply  circuit. For example, the power supply is dimmable with PWM (Pulse Width Modulation) , or amplitude modulation or a combination of PWM and amplitude modulation.
In an embodiment, the additional capacitor may be inserted in parallel with a capacitor of the LLC converter.
In an embodiment, the capacitance of the additional capacitor may be determined according to actual requirements.
As shown in Fig. 1, the additional capacitor is a capacitor C9.
The LLC converter includes an inductor L1, diodes D1, D2, D3, D4, D10, field effect transistors Q1, Q2, resistances R1, R2, transformer TX1, and capacitors C2, C3, C5, C8, C10. Functions of these parts may be similar to those in the related art, and more details shall not be described herein any further.
As shown in Fig. 1, the additional capacitor C9 is inserted in parallel with the capacitor C5 of the LLC converter.
As shown in Fig. 1, the passive power factor correction (PPFC) circuit includes diodes D5, D6, D7, D8, D9, capacitors C1 and C4. The charge pump circuit may include the capacitor C1 and the diode D9, which provide charge pump boosting for the capacitor C4. Functions of these parts may be similar to those in the related art, and more details shall not be described herein any further.
In an embodiment, the power supply circuit may further include a filter circuit.
As shown in Fig. 1, the filter circuit includes inductor L2 and capacitors C6, C7.
In an embodiment, the power supply circuit may further include a first switch used to turn on the additional capacitor when a predetermined condition is satisfied.
In an embodiment, the predetermined condition may be a harmonic requirement being not met.
In an embodiment, the first switch includes two field effect transistors (FETs) .
As shown in Fig. 1, the first switch includes FETs Q3 and Q4, which control  bilateral directions of current flowing through the additional capacitor C9, so as to switch the additional capacitor C9. The FETs Q3 and Q4 are connected to the capacitor C10 of the LLC converter, so as to be able to provide power for the additional capacitor C9 when the additional capacitor C9 is turned on by the FETs Q3 and Q4. In addition, a resistance R3 may be included in the first switch.
In an embodiment, the power supply circuit may further include a driver used to drive the first switch to turn on the additional capacitor when the predetermined condition is satisfied.
In an embodiment, the driver may include an isolator and a controller.
In an embodiment, the isolator may be any type of isolator. For example, the isolator is an optocoupler.
In an embodiment, the controller may be any type of controller. For example, the controller is a microcontroller unit (MCU) .
As shown in Fig. 1, the driver includes an optocoupler U1 and a MCU. The optocoupler U1 is also connected to the capacitor C10 of the LLC converter, so as to be able to provide auxiliary power for the additional capacitor C9 when the additional capacitor C9 is turned on by the FETs Q3 and Q4.
In an embodiment, the MCU is used to control the optocoupler U1 to drive the FETs Q3 and Q4 according to a harmonic requirement.
For example, when the harmonic requirement is not met, the MCU controls the optocoupler U1 to drive the FETs Q3 and Q4 to turn on the additional capacitor C9. Then more power may be provided for the charge pump circuit, thus the pump charge boosting of the PPFC circuit is increased.
In an embodiment, the harmonic may not be detected directly. Voltages and current of a primary transformer of the LLC converter may be detected to estimate a status of the harmonic.
In an embodiment, the voltages and current of the primary transformer of the  LLC converter may be detected by using existing methods.
Fig. 2 is a diagram of detecting results of the voltages and current of the primary transformer of the LLC converter with an embodiment of the present disclosure.
As shown in Fig. 2, the upper curve represents the maximum voltages of the primary transformer of the LLC converter, and the curve below represents the minimum voltages of the primary transformer of the LLC converter. When the two curves are overlapping to each other, the FETs Q3 and Q4 shall be driven to turn on the additional capacitor C9 by the optocoupler U1 and the MCU.
For example, detecting results of the voltages and current of the primary transformer of the LLC converter may be acquired by the MCU. Then the MCU controls the optocoupler U1 to drive the FETs Q3 and Q4 to turn on the additional capacitor C9 when the two curves of the voltages and current of the primary transformer of the LLC converter are overlapping to each other.
In an embodiment, other constructions and functions of the power supply circuit may be similar to those in the related art, and more details of these parts shall not be described herein any further.
As can be seen from the above embodiments, an additional capacitor is used to change capacitance of the LLC converter. Thus, the pump charge boosting of the PPFC circuit is increased, and the ranges of output voltage and output current are wider. The dimming application is possible. Furthermore, harmonic requirement is easily met with low cost.
Second embodiment
A power supply circuit is provided in a second embodiment.
Fig. 3 is another diagram of a power supply circuit with an embodiment of the present disclosure.
As shown in Fig. 3, the power supply circuit includes:
a passive power factor correction (PPFC) circuit, including a charge pump circuit;
a LLC converter; and
an additional capacitor used to change capacitance of the charge pump circuit.
In an embodiment, the power supply circuit may be provided for a lamp. For example, the power supply circuit is a LED power supply circuit.
In an embodiment, the power supply circuit may be any type of power supply circuit. For example, the power supply is dimmable with PWM (Pulse Width Modulation) , or amplitude modulation or a combination of PWM and amplitude modulation.
In an embodiment, the additional capacitor may be inserted in parallel with a capacitor of the charge pump circuit.
In an embodiment, the capacitance of the additional capacitor may be determined according to actual requirements.
Similar to the first embodiment, as shown in Fig. 3, the additional capacitor is the capacitor C9.
The passive power factor correction (PPFC) circuit includes diodes D5, D6, D7, D8, D9, capacitors C1 and C4. The charge pump circuit may include the capacitor C1 and the diode D9, which provide charge pump boosting for the capacitor C4. Functions of these parts may be similar to those in the related art, and more details shall not be described herein any further.
The additional capacitor C9 is inserted in parallel with the capacitor C1 of the charge pump circuit.
Similar to the first embodiment, the LLC converter includes an inductor L1, diodes D1, D2, D3, D4, D10, field effect transistors Q1, Q2, resistances R1, R2, transformer TX1, and capacitors C2, C3, C5, C8, C10. Functions of these parts may be similar to those in the related art, and more details shall not be described herein any further.
In an embodiment, the power supply circuit may further include a filter circuit.
As shown in Fig. 3, the filter circuit includes inductor L2 and capacitors C6, C7.
In an embodiment, the power supply circuit may further include a second switch used to turn on the additional capacitor when a predetermined condition is satisfied.
In an embodiment, the predetermined condition may be a harmonic requirement being not met.
In an embodiment, the second switch includes one field effect transistors (FETs) .
As shown in Fig. 3, the second switch includes the FET Q3, which control one direction of current flowing through the additional capacitor C9, so as to switch the additional capacitor C9. The FET Q3 is connected to the capacitor C10 of the LLC converter, so as to be able to provide power for the additional capacitor C9 when the additional capacitor C9 is turned on by the FET Q3.
As shown in Fig. 3, the charge pump circuit includes the diode D9, which control the other direction of current flowing through the additional capacitor C9. Thus, only one FET Q3 is needed to switch the additional capacitor C9 and lower cost is needed. Furthermore, it doesn’t have impact on the quality factor of the LLC converter, and the implement is easier.
In an embodiment, the power supply circuit may further include a driver used to drive the second switch to turn on the additional capacitor when the predetermined condition is satisfied.
In an embodiment, the driver may include an isolator and a controller.
In an embodiment, the isolator may be any type of isolator. For example, the isolator is an optocoupler.
In an embodiment, the controller may be any type of controller. For example, the controller is a microcontroller unit (MCU) .
Similar to the first embodiment, as shown in Fig. 3, the driver includes the  optocoupler U1 and the MCU. The optocoupler U1 is also connected to the capacitor C10 of the LLC converter, so as to be able to provide auxiliary power for the additional capacitor C9 when the additional capacitor C9 is turned on by the FET Q3.
In an embodiment, the MCU is used to control the optocoupler U1 to drive the FET Q3 according to a harmonic requirement.
For example, when the harmonic requirement is not met, the MCU controls the optocoupler U1 to drive the FET Q3 to turn on the additional capacitor C9. Then more power may be provided for the charge pump circuit, thus the pump charge boosting of the PPFC circuit is increased.
In an embodiment, the harmonic may not be detected directly. Voltages and current of a primary transformer of the LLC converter may be detected to estimate a status of the harmonic.
Similar to the first embodiment, as shown in Fig. 2, when the two curves are overlapping to each other, the FET Q3 shall be driven to turn on the additional capacitor C9 by the optocoupler U1 and the MCU.
For example, detecting results of the voltages and current of the primary transformer of the LLC converter may be acquired by the MCU. Then the MCU controls the optocoupler U1 to drive the FET Q3 to turn on the additional capacitor C9 when the two curves of the voltages and current of the primary transformer of the LLC converter are overlapping to each other.
In an embodiment, other constructions and functions of the power supply circuit may be similar to those in the related art, and more details of these parts shall not be described herein any further.
As can be seen from the above embodiments, an additional capacitor is used to change capacitance of the charge pump circuit. Thus, the pump charge boosting of the PPFC circuit is increased, and the ranges of output voltage and output current are wider. The dimming application is possible. Furthermore, harmonic requirement is easily met with low cost.
Generally, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.
Although the present disclosure has been described in language specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims (14)

  1. A power supply circuit, comprising:
    a passive power factor correction (PPFC) circuit, comprising a charge pump circuit;
    a LLC converter; and
    an additional capacitor used to change capacitance of the LLC converter or the charge pump circuit.
  2. The power supply circuit according to claim 1, wherein,
    the additional capacitor is inserted in parallel with a capacitor of the LLC converter.
  3. The power supply circuit according to claim 2, wherein, the power supply circuit further comprises:
    a first switch used to turn on the additional capacitor when a predetermined condition is satisfied.
  4. The power supply circuit according to claim 3, wherein,
    the first switch comprises two field effect transistors (FETs) .
  5. The power supply circuit according to claim 1, wherein,
    the additional capacitor is inserted in parallel with a capacitor of the charge pump circuit.
  6. The power supply circuit according to claim 5, wherein, the power supply circuit further comprises:
    a second switch used to turn on the additional capacitor when the predetermined condition is satisfied.
  7. The power supply circuit according to claim 6, wherein,
    the second switch comprises one field effect transistor (FET) .
  8. The power supply circuit according to claim 3 or 6, wherein, the power supply circuit further comprises:
    a driver used to drive the first switch or the second switch to turn on the additional capacitor when the predetermined condition is satisfied.
  9. The power supply circuit according to claim 8, wherein,
    the driver comprises an isolator and a controller.
  10. The power supply circuit according to claim 9, wherein,
    the controller is used to control the isolator to drive the first switch or the second switch according to a harmonic requirement.
  11. The power supply circuit according to claim 9, wherein,
    the controller is used to control the isolator to drive the first switch or the second switch according to detecting results of voltages and current of a primary transformer of the LLC converter.
  12. The power supply circuit according to claim 9, wherein,
    the isolator is an optocoupler.
  13. The power supply circuit according to claim 9, wherein,
    the controller is a microcontroller unit (MCU) .
  14. The power supply circuit according to any one of claims 1-13, wherein,
    the power supply circuit is a LED power supply circuit.
PCT/CN2018/124966 2018-12-28 2018-12-28 Power supply circuit Ceased WO2020133243A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4133585A4 (en) * 2020-05-29 2023-05-31 Tridonic GmbH & Co KG CHARGE PUMP CONTROL DEVICE AND METHOD

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101656468A (en) * 2008-08-20 2010-02-24 深圳桑达百利电器有限公司 High-frequency passive power factor correction circuit and high-frequency passive power factor correction method
CN101686007A (en) * 2008-09-27 2010-03-31 奥斯兰姆有限公司 Starting circuit for integrated circuit of power factor correction controller
CN101860193A (en) * 2010-05-05 2010-10-13 张逸兴 Power factor correction circuit
US20130127357A1 (en) * 2010-01-15 2013-05-23 Koninklijke Philips Electronics N.V. Power factor correction circuit of an electronic ballast
CN207219095U (en) * 2017-07-31 2018-04-10 昂宝电子（上海）有限公司 Led drive circuit
WO2018166501A1 (en) * 2017-03-16 2018-09-20 Tridonic Gmbh & Co Kg Driver with charge pump circuit

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101656468A (en) * 2008-08-20 2010-02-24 深圳桑达百利电器有限公司 High-frequency passive power factor correction circuit and high-frequency passive power factor correction method
CN101686007A (en) * 2008-09-27 2010-03-31 奥斯兰姆有限公司 Starting circuit for integrated circuit of power factor correction controller
US20130127357A1 (en) * 2010-01-15 2013-05-23 Koninklijke Philips Electronics N.V. Power factor correction circuit of an electronic ballast
CN101860193A (en) * 2010-05-05 2010-10-13 张逸兴 Power factor correction circuit
WO2018166501A1 (en) * 2017-03-16 2018-09-20 Tridonic Gmbh & Co Kg Driver with charge pump circuit
CN207219095U (en) * 2017-07-31 2018-04-10 昂宝电子（上海）有限公司 Led drive circuit

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4133585A4 (en) * 2020-05-29 2023-05-31 Tridonic GmbH & Co KG CHARGE PUMP CONTROL DEVICE AND METHOD

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